I did a thorough search of after-market filters the first time I went through my tractor. While I did get an after-market filter at NAPA, it was actually more expensive than the factor Kubota filter. I've found that all of the after-market filters I've found, at least the engine oil and hydraulic fluid filters, are NOT significantly less expensive than Kubota brand. I also recommend getting factory filters from someone like tractorsmart.
I did a thorough search of after-market filters the first time I went through my tractor. While I did get an after-market filter at NAPA, it was actually more expensive than the factor Kubota filter. I've found that all of the after-market filters I've found, at least the engine oil and hydraulic fluid filters, are NOT significantly less expensive than Kubota brand. I also recommend getting factory filters from someone like tractorsmart.